/* Copyright (c) 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.wave.api.event;

import com.google.wave.api.Blip;
import com.google.wave.api.Wavelet;
import com.google.wave.api.impl.EventMessageBundle;

/**
 * Object describing a single event, that captures changes made to a
 * wavelet or blip in a wave.
 */
public interface Event {

  /**
   * Returns the type of the event.
   *
   * @return the type of the event.
   */
  EventType getType();

  /**
   * Returns the wavelet in which this event occurs.
   *
   * @return the wavelet in which this event occurs.
   */
  Wavelet getWavelet();

  /**
   * Returns the blip in which this event occurs, or the root blip for a wavelet
   * event.
   *
   * @return the blip in which this event occurs, or the root blip.
   */
  Blip getBlip();

  /**
   * Returns the id of the participant that triggered this event.
   *
   * @return the id of the participant that triggered this event.
   */
  String getModifiedBy();

  /**
   * Returns the timestamp when this event occurred on the server.
   *
   * @return the timestamp of the event.
   */
  long getTimestamp();

  /**
   * Returns the message bundle which this event belongs to.
   *
   * @return the message bundle object.
   */
  EventMessageBundle getBundle();
}
